ST just updated their Google Home integration. You might want to read about it in this topic.
This two ST account, two Google account came up earlier as well. There is another topic about this, where you can ask. Unfortunately I cannot find it…
But try the following, ST is shared with your wife, she can control with the ST app. You set up your account with Google Home, then you share your Google Home with your wife’s account. No cross adding things and defining two homes…
Tagging @oldcomputerwiz, who went through this recently and might can help explain in details.